Defoliation
Interview: Should You Defoliate Your Plants? A Conversation on Plant Energy and Growth
Caller: Hey Aquaponic Dumme, I’ve been seeing a lot of mixed advice online about defoliation. Some growers say to strip off a bunch of leaves for better light, others say to leave them alone. What’s the right move here?
Aquaponic Dumme: Before cutting anything, it’s important to understand a bit of plant biology. Once you know how plants actually use and move energy, it becomes clear when and why to remove leaves—if at all.
Caller: Alright, so what’s the science behind it?
Aquaponic Dumme: Plants have two main types of tissues when it comes to energy: sources and sinks. Large, mature leaves are sources—they’ve slowed down in growth, so they don’t use much energy. Instead, they produce sugars through photosynthesis and send that energy to the rest of the plant.
Caller: So those big fan leaves are actually helping the plant, not blocking it?
Aquaponic Dumme: Exactly. They’re like solar panels. Removing them means removing the plant’s main energy producers. Smaller, immature leaves, on the other hand, are sinks. They’re still growing, so they use up more energy than they make.
Caller: So the small leaves are kind of freeloaders?
Aquaponic Dumme: In a sense, yes. They’re necessary early on, but too many of them can drain resources. The key is knowing when to remove them. During the vegetative stage, it’s best not to remove anything. The plant is still building its structure and needs all the energy it can get.
Caller: When does defoliation actually make sense then?
Aquaponic Dumme: About two weeks before switching to the flowering stage. That’s when you want to maximize your sources—the big, mature leaves—and remove unnecessary sinks. At that point, the only sinks you really want are the flowers themselves.
Caller: I’ve heard people say removing leaves helps the buds get more light and grow faster. Is that true?
Aquaponic Dumme: Not really. That’s a common misunderstanding. Removing leaves doesn’t make the plant grow faster. What it can do is redirect energy by removing sinks that compete with the flowers. But the flowers themselves don’t need light the way leaves do—they can’t process light photons for energy.
Caller: Wait, flowers don’t need light?
Aquaponic Dumme: Not directly. Flowers don’t photosynthesize like leaves. In fact, too much light can degrade THC into CBN, which reduces potency. So the idea that leaves block light from buds is a myth.
Caller: That’s interesting. I’m more of a visual learner though—this whole source and sink thing sounds a bit abstract.
Aquaponic Dumme: Then check out the YouTube channel Mr. DeBacco. He’s got a great visual explanation of sources and sinks that really helps make the concept click. Seeing it visually makes it much easier to understand how energy moves through the plant.
Caller: Got it. So basically, keep the big leaves, remove only what’s draining energy, and don’t overdo it?
Aquaponic Dumme: Exactly. Defoliation should be strategic, not routine. Think of it as managing the plant’s energy flow—keep the producers, trim the consumers, and let the plant do the rest.
References:
Comprehensive Analytical Chemistry, 2020
Matthew J. Paul, Christine H. Foyer, July 2001
Tian-Gen Chang, Xin-Guang Zhu, February 2017
